JPH0830674B2 - Viscosity or density meter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscometer or a density meter adapted to transmit vibration of a vibrator made of piezoelectric ceramic or the like through a vibrating shaft to a test sample immersed in a measuring solution, and particularly to the above-mentioned elements. The present invention relates to a support structure for a vibration unit including a.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 5-20692 owned by the applicant
In No. 3, the vibration axis is directly connected to the circular oscillator, and the test piece is directly connected to the end of this vibration axis to form the vibration unit.
The vibration of the vibrator is transmitted to the test piece through the vibration shaft.

Further, this kind of vibrating unit must be supported so as to be vibrationally insulated from the casing for accommodating the vibrator, the measurement liquid container or the liquid passage pipe. The mass body provided at the opposite end is suspended from the casing via a cushioning material such as rubber.

[0004]

However, as in the conventional example, the upper end of the vibrating unit (the upper end side of the vibrator) is stably suspended from the casing through the mass body, and the vibration of the vibrator is vibrated. On the other hand, in order to keep the mass body static, it is required to use a large-sized mass body having a considerable weight with respect to the total weight of the vibration unit. are doing.

Further, in the prior art, a flat disc-shaped seal plate is provided as a means for insulating between the vibrator and the test sample immersed in the test solution from the test solution. However, this disc-shaped sealing plate acts as a rigid body against the vibration in the circular direction and may impede proper vibration, and there is a problem that the vibration transmission to the analyzer is impaired.

The above problems are also solved when the vibrating unit is imaginarily supported on a container or pipe for measuring liquid and the test piece is immersed in the measuring liquid to measure viscosity or density on a regular basis. Has become.

[0007]

SUMMARY OF THE INVENTION The present invention is provided for the purpose of solving the above problems. As its means, there is provided a vibration coupling cylinder that vibrates in a circular direction together with the vibration shaft of the vibration unit. The vibration coupling body is externally inserted at a distance, one end and the other end of the vibration coupling body are fixed to the vibration shaft, and a mounting member for imaginarily supporting the vibration unit is attached in the middle of the vibration coupling cylinder, and one side of the mounting member is mounted. A vibration coupling tube portion protruding to the other side and a vibration coupling tube portion projecting to the other side are formed so that vibration is transmitted from the vibrator to the analyzer by a vibration axis.

According to the basic concept of the present invention, the structure as described in the subordinate claims is adopted.

[0009]

According to the present invention, since the vibrating unit is imaginarily supported by mounting the mounting member in the middle of the vibration coupling cylinder that vibrates together with the vibrating shaft, both vibration coupling cylinder portions divided by the mounting member are circular. Good vibration is easily induced against the vibration of the vibration axis. Therefore, the vibration is properly transmitted to the analyzer without disturbing the vibration of the vibration shaft in the circular direction. Can be firmly fixed against
Even if it is firmly fixed, the above-mentioned vibration transmission is not impaired, and it is possible to eliminate the disturbance factors associated with aerial support as much as possible and to perform highly reliable measurement.

The present invention is most suitable as an aerial support structure for a detection unit in the case of resonating a tester with a vibrator.

[0011]

Embodiments of the present invention will be described in detail below with reference to FIGS.

Reference numeral 1 denotes a vibrator that vibrates in a circular direction around a vibration axis Z, and a vibration shaft 2 having the circular vibration axis Z as an axis is directly connected to the vibrator 1 and the end of the vibration shaft 2 is connected. A probe 3 having an axis of the vibration axis Z is directly connected to the portion to form a vibration unit.

When the vibrator 1 vibrates in a circular direction about the axis Z, the vibration is transmitted to the test sample 3 via the vibration shaft 2, and the test sample 3 is immersed in the test solution 4, The viscous resistance and the inertial mass of the liquid 4 are sensed by the vibration in the liquid.

As the circular oscillator 1, there is
Of the torsional oscillator disclosed in FIGS. 6 and 7 of 20692, or the torsional oscillator disclosed in FIGS. 3, 9 and 10 of Japanese Patent Publication No. 5-20693. Applicable. Any of these can give a circular vibration about the axis Z to the vibration shaft 2 and the analyzer 3.

Most of the vibrator 1 and the vibration shaft extending from the vibrator 1 are housed in a casing 5, and the end opening 7 of the casing 5 is directly connected to the shaft end of the vibration shaft 2 and the shaft end. The test piece 3 is exposed to the outside.

A mounting member 6 is integrally attached to the end of the casing 5 on the side of the analyzer 3. The mounting member 6 is a means for mounting and fixing the detection unit covered with the casing 5 on the outer wall 8 of the container 11 or the pipe holding the measurement liquid, and preferably the mounting member 6 is the opening 9 for mounting the container 11 or the pipe. To form a lid that closes.

In order to function as the lid body, the mounting member 6 can be formed by a flange projecting annularly around the casing 5, and a plurality of mounting holes 10 are provided in the flange, and the mounting body 6 is formed by the lid body. The opening 9 is closed and fixed to the container 11 or the outer wall 8 of the pipe through the mounting hole 10.

The shaft end of the vibrating shaft 2 and the tester 3 attached to the shaft end project outwardly from the casing 5 through a through hole 12 provided at the center of the mounting member 6. The vibration coupling cylinder 13 is externally inserted in the middle of the vibration shaft 2 formed as described above. This vibration coupling cylinder 13 has a vibration shaft 2 formed by a vibrator 1.
It is made of a thin metal or resin that can vibrate in response to the vibration of.

Between the inner peripheral surfaces of the vibration coupling cylinder 13 and the vibration shaft 2
An annular gap 14 is formed between the outer peripheral surfaces of the two, and one end and the other end of the vibration coupling cylinder 13 are integrally fixed to the vibration shaft 2.
The vibration shaft 2 extends along the axis Z of the vibration coupling cylinder 13 with the gap 14 therebetween, and the vibration shaft portion 2a existing in the coupling cylinder 13 is made larger in diameter than the vibration shaft portion extending outside the coupling cylinder 13. The shaft portion 2a is set to have a rigidity higher than that of the vibration coupling cylinder 13.

The mounting member 6 is integrally mounted in the middle of the vibration coupling cylinder 13. As a means for attaching the mounting member 6 to the vibration coupling cylinder 13, for example, a flange 15 is integrally projected in the middle of the coupling cylinder 13, preferably in the center, and the flange 15 is inserted in the center of the flange forming the mounting member 6. It is made into an integral structure by welding, press fitting or adhesion.

For example, the vibrator 1 is set to a vibration mode in which the analyzer 3 is driven at a frequency that resonates, and the vibration shaft 2 has a vibration node (vibration zero) O in the middle of its extension length. Therefore, the vibrating shaft 2 resonates so that the shaft portion 2b extending to one end side of the node O and the shaft portion 2c extending to the other end side thereof induce circular vibrations in opposite directions. .

The flange serving as the mounting member 6 has a mounting portion for the vibration coupling cylinder 13 in the middle of the vibration coupling cylinder 13, preferably at a position corresponding to the node O or in the vicinity thereof. Therefore, the flange 15 protruding from the middle of the vibration coupling cylinder 13 is also arranged at a position corresponding to the node O or in the vicinity thereof.

The vibration coupling cylinder 13 is divided into two parts by the mounting member 6 and the flange 15, and the coupling cylinder part 13a projecting to one surface side of the mounting member 6 and the coupling cylinder part projecting to the other surface side of the mounting member 6 centering on the joint O. Part 1
3b is formed. Therefore, according to the principle of resonance, the coupling cylinder portions 13a and 13b vibrate in the circular directions in opposite directions with the node O as the center, and the node O has no vibration. Desirably, the coupling cylinder portions 13a and 13b are made symmetrical with respect to the node O so that their spring constants are set substantially equal.

The probe 3 protruding from one end of the vibration coupling cylinder 13 and the shaft end portion 2b of the vibration shaft 2 supporting the same are screwed into the ends of the vibration shaft portion 2a extending in the vibration coupling cylinder 13. The vibrating shaft portion 2c, which is integrally connected by virtue of the above, and which similarly projects from the other end of the vibrating coupling cylinder 13, is integrally screwed to the other end of the vibrating shaft portion 2a extending in the vibrating coupling cylinder 13. Combine,
A sealing structure is formed at each of the connecting portions, and at least the open end portion of the vibration coupling cylinder 13 on the side of the probe 3 is closed at the connecting portion with the vibration shaft portion 2b. The measurement liquid that has penetrated from 3 to the surface of the shaft portion 2b and infiltrates in the direction of the vibrator 1 is cut off in the sealed portion.

On the other hand, the mounting member 6 is a container 11
Insulate the inside or inside and outside of the pipe from the measured solution.
Therefore, it can be suitably carried out when it is attached to the outer wall of a liquid storage tank or pipe in a petroleum refining line or a chemical reaction tank and the viscosity or density of the liquid is routinely measured.

The vibrating shaft 2 detects the vibration of the vibrator 1 by the tester 3
Means a member extending along the vibration axis Z transmitted to the shaft, including the case where the entire length is made equal in diameter, or the case where a part of the shaft extending portion is made large or small in diameter. In FIG. 1, reference numeral 16 is a vibration sensor attached to the end of the vibration unit on the side opposite to the test piece 3, and the vibration sensor 16 detects the measurement solution and the load on the vibrator 1 changes. Sometimes this change is detected and a signal corresponding to this detection is output to the arithmetic unit via the cable 17. This arithmetic unit may be provided in the casing 5.

The vibration sensor 16 is similar to the vibrator 1 in that
For example, using the voltage-driven piezoelectric element shown as the conventional example, a change in mechanical vibration (a change in vibration due to a change in resistance received by the test sample 3) is converted into a voltage signal and output. Further, the vibrator 1 applies a voltage via the cable 17 to cause mechanical vibration (circular vibration).

[0028]

According to the present invention, when the vibrating unit is supported on the casing or the measurement liquid holding object, the vibrating unit can be properly supported by the mounting member via the vibrating coupling tube configured as described above. Since it is supported on the mounting member via the vibration, damping of the vibration at the supporting part is suppressed as much as possible, and the vibration of the vibrator is satisfactorily transmitted to the test sample via the vibration axis for sound measurement. You can In addition, the vibration unit does not increase in size and weight as in the case of supporting it through a mass body having a required weight, and contributes to reduction in size and weight. Further, the vibrating unit can be firmly attached through the vibrating coupling cylinder and the mounting member, and shaft runout due to the flow velocity resistance of the measurement liquid and the liquid sensitive resistance of the analyzer can be effectively prevented and stably supported. Further, a structure for achieving watertightness can be easily formed by the coupling portion of the vibration coupling cylinder, and the mounting member can function as a lid that closes the detection unit mounting opening in the measurement liquid storage portion. It is possible to satisfactorily shut off the measurement liquid held in the container and properly perform the measurement by the detection unit attached to the lid.

[Brief description of drawings]

FIG. 1 is a sectional view of a viscosity or density meter showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a cross-sectional view showing a usage state of the viscosity or density meter.

[Explanation of symbols]

 1 vibrator 2 vibrating shaft 3 analyzer 6 mounting member 13 vibration coupling cylinder O section

Claims (4)

[Claims] 1. A vibrating unit in which an end of a vibrating shaft which is vibrated in a circular direction by a vibrator is integrally provided with a test sample immersed in a measuring liquid, and the vibrating shaft vibrates in a circular direction together with the vibrating shaft. The vibration coupling cylinder is externally inserted at intervals, one end and the other end of the vibration coupling cylinder are fixed to the vibration shaft, and a mounting member for supporting the vibration unit is attached to the middle of the vibration coupling cylinder. And a viscosity or densitometer. 2. The viscosity or density meter according to claim 1, wherein the mounting member forms a lid that closes an opening for mounting the measurement liquid container. 3. The viscosity or density meter according to claim 1, wherein the mounting member is mounted near a vibration node of the vibration shaft. 4. A spring constant of a vibration coupling cylinder part on one end side divided by the mounting member and a spring constant of a vibration engagement cylinder part on the other end side thereof are set to be substantially equivalent. Item 1, 2 or 3 viscosity or density meter.